Project Summary Recent preclinical and clinical results have demonstrated the safety and efficacy of nanoparticle-amplified radiation therapy. In parallel, MR-guided radiation therapy is an emerging paradigm that would benefit from specific contrast agents. This Academic- Industrial Partnership will leverage these current trends by designing, developing and rigorously testing a novel nanoparticle for MR-guided radiation therapy. Our supporting data consists of extensive physical and biological characterization of gadolinium and bismuth-gadolinium based nanoparticles, including in vivo biodistribution, imaging and therapy results in multiple tumor models. In this project, we will develop and optimize a direct high-yield synthesis process for bismuth-gadolinium nanoparticles and perform extensive toxicity and therapy evaluation in a translational model under clinical delivery schedules and conditions. Our innovative and highly translatable imaging and therapy concept is compatible with current and emerging clinical practice and could offer a substantial clinical benefit with minimal patient risk.